Performance Tuning - Question 064.

Which of the following is true about the physical guess on an IOT?

A . Following a failed or incorrect guess, access is via the UROWID.

B . The physical guess is updated when a block splits.

C. Following a failed or incorrect guess, access is via the primary key.

D . Following a failed or incorrect guess, access is via the secondary key.

E . The physical guess is the same thing as the physical ROWID on heap-organized tables.

Explanation:

Answer C: The physical guess is a ROWID guess of the actual location of a row in the IOT. If, for whatever reason, a row moves in an IOT, the physical guess becomes invalid. The primary key is then used for IOT lookup; the primary key is slower.